The invention relates in the first instance to a method for embedding a cable or the like into an underwater ground, in which method the cable is introduced into a zone of reduced density which is produced progressively in the underwater ground by a flushing process.
Furthermore, the invention relates to an apparatus which is suitable for performing the method, for the embedding of cables and the like into an underwater ground; the apparatus comprising an embedding vehicle which is movable, preferably drivable, on the underwater ground, the embedding vehicle having a guide device being in guiding relationship with the cable to be embedded; and a flushing colter which is adjustable to various flushing depths below the vehicle, the colter comprising at least one cable channel and being provided with flushing nozzles, the colter preferably being pivotable about a transverse axis of the embedding vehicle to thereby adjust the colter to different flushing depths, the colter preferably being coupled to a vibration device and preferably being provided with tearing teeth.
The method and the apparatus of the kind described above are known, for example from the U.S. Pat. No. 3,333,432.
In numerous cases of application, it is not possible to draft a cable laying path which extends throughout through ground formations suitable for flush-embedding. In such cases, the laying path hitherto was drafted so that it comprises as few as possible, and continuous, sections through more solid ground formations which are not suited for being fluidized by a flushing process. Then, those sections were especially preparated for the embedding process, for instance by blasting a trench, prior to the embedding operation proper which for the rest was performed by a flushing process. Such preparatory work requires a high expense with respect to labour time and the use of special devices for the working of the underwater ground. Thereby, the typical advantages of the flushing process, particularly its high speed of operation, and its economy, were practically completely destroyed in many cases.
It is the object of the invention to provide a method and an apparatus for embedding a cable or the like into an underwater ground, in which the typical advantages of the flushing or fluidizing technique are retained even if non-flushable ground formations occur in sections of the laying path.